Explanations:The Hooghly River, a major distributary of the Ganges, flows through the city of Kolkata and is an important geographical feature of the region. Several bridges span the Hooghly River, connecting different parts of the city and facilitating transportation. Among these, the Howrah Bridge and the Vidyasagar Setu are two of the most significant and well-known structures.
The Howrah Bridge, also known as the Rabindra Setu, is a suspension bridge that connects the city of Kolkata with the suburb of Howrah. It is one of the busiest bridges in the world and a major landmark of Kolkata. The bridge was completed in 1943 and is known for its distinctive design and the fact that it is made entirely of steel, without any nuts or bolts.
The Vidyasagar Setu, also known as the Second Hooghly Bridge, is a cable-stayed bridge that was completed in 1992. It is named after the renowned Bengali polymath Ishwar Chandra Vidyasagar. This bridge is a significant engineering achievement and serves as a vital link between the eastern and western parts of Kolkata, reducing traffic congestion on the Howrah Bridge.
Both the Howrah Bridge and the Vidyasagar Setu are built on the Hooghly River, making them important structures in the city's infrastructure. The Mahatma Gandhi Setu, on the other hand, is located in Patna, Bihar, and spans the Ganges River, not the Hooghly. Therefore, the correct answer is that both the Howrah Bridge and the Vidyasagar Setu are built on the Hooghly River, as stated in option D.
Understanding the geographical context and the specific locations of these bridges is crucial for answering questions related to the infrastructure and geography of Kolkata. The Hooghly River plays a significant role in the city's history and development, and the bridges that span it are not only important for transportation but also serve as iconic landmarks of the city.